Invasion biology of the cotton mealybug, Phenacoccus solenopsis Tinsley: Current knowledge and future directions

The cotton mealybug Phenacoccus solenopsis Tinsley(Hemiptera: Pseudococcidae), which is native to North America, emerged as a major invasive insect pest of multiple crops in Asia at the beginning of the 21 st century. Considering the economic significance of this insect and its rapid worldwide spread, we examined the possible factors driving its invasions. In this paper, we summarize the life history traits of P. solenopsis conceivably related to population development in invaded regions; these traits include its use of diverse host plants, reproductive capacity and mode, adaptation to temperature, response to food shortage, and insecticidal resistance. Then, focusing on the multiple trophic interactions that may promote or hinder invasion, we review the mutualistic relationship of this mealybug with ants and predation and parasitism by natural enemies. Finally, we suggest topics for future research and provide our perspective on the biological invasions of this mealybug. We speculate that specific biological factors associated with this mealybug, particularly its wide host range, high reproductive potential, evolved changes in life history traits, and mutualism with ants have played important roles in its invasions, allowing this pest to become established and rapidly increase its population upon its introduction into new regions.

Species-specific COI primers for rapid identification of a globally significant invasive pest, the cassava mealybug Phenacoccus manihoti Matile-Ferrero

The globally invasive cassava mealybug Phenacoccus manihoti Matile-Ferrero is a pernicious pest of cassava,and its recent introduction into Asia has raised considerable alarm.To slow or prevent further invasion,an accurate,simple,and developmental-stage-independent detection method for P.manihoti is required.In the present study,a PCR method based on a species-specific mitochondrial DNA cytochrome oxidase I(SS-COI)marker was developed for rapid identification of P.manihoti.One pair of SS-COI primers(PMSSZW-1F and PMSSZW-1R)was designed based on sequence variations in the COI gene among P.manihoti and related mealybug species.Specificity of the primer pair was validated on 21 closely related species.Sensitivity tests were performed on four immature developmental stages and female adults.Efficacy tests demonstrated that at the relatively low concentration of(135.2±14.7)pgresuspended DNA,the specific fragment was detected in all replicates.Furthermore,the SS-COI primer pair was assayed on three populations of P.manihoti from major exporting countries of cassava.The PCR assay was proved to be a rapid,simple,and reliable molecular measure for the identification of P.manihoti.This tool will be useful for quarantine,monitoring,and management of this invasive pest.

Preferential feeding of an anthocorid predator Blaptostethus pallescens Poppius on different stages of cotton mealybug

Blaptostethus pallescens Poppius (Heteroptera:Anthocoridae),which is amenable to mass rearing,has proved to be a potential predator of sucking pests like mites and thrips.Recently,the cotton mealybug Phenacoccus solenopsis Tinsley emerged as a serious pest on cotton in India.Laboratory studies indicated that B.pallescens could feed on the cotton mealybug.Hence,further investigations were conducted to understand the stage of the predator which is most potential and the pest stage preferred by the predator.Mature nymphs and adults of B.pallescens could predate equally well on the neonates of cotton mealybug.Young (three to four-day-old) nymphs of the predator could not feed on any stage of the cotton mealybug.Mature nymphs (seven-day-old and above) and adults could effectively predate on both young and mature cotton mealybug crawlers,though preference was more for the younger crawlers.However,nymphs and adults of B.pallescens could not predate on the adult stage of the mealybug.Different predator:pest ratios were tested in cage studies and it emerged that B.pallescens adults released against the mealybug crawlers at a ratio of 1:5 and nymphal release at 1:10 caused maximum mortality of the mealybug crawlers.Considering the fast multiplication rate of cotton mealybug and the large number of predators which have to be released to manage them,further detailed studies are necessary on utilizing B.pallescens to target the neonates and younger stages of the cotton mealybug in field conditions.

Establishment of Real-time Fluorescent Quantitative PCR for Pineapple mealybug wilt associated virus-3

[ Objective ] The paper aimed to establish a real-time fluorescent quantitative PCR （qPCR） detection method for Pineapple mealybug wilt associated vi- rus-3 （ PMWaV3 ）. [ Method] Specific TaqMan probe and primers were designed and synthesized according to the conserved sequence of coat protein（CP） gene of PMWaV-3, and the standard curve was established after optimizing the amplification condition of qPCR. [ Result] The results showed that the method was specific for the detection of PMWaV-3, and the sensitivity of the present method was about 10 times higher compared to general RT-PCR ; the variation coefficients of intra- assay and inter-assay were less than 1.73, respectively. [ Conclusion] The qPCR is an easy, fast and reliable method for quantitative detection of PMWaV-3.

Green Synthesis of Bimetallic Nanoparticles From Prosopis juliflora(Sw)DC.,and Its Effect Against Cotton Mealybug,Phenacoccus solenopsis(Hemiptera:Pseudococcidae)

Phenacoccus solenopsis has been recognized as an aggressively invasive species on cotton plants in different countries.This study was conducted to investigate the effect of green synthesized Cu/Zn-nanoparticles using aqueous leaf extract of Prosopis juliflora(mezquite)against P.solenopsis.The scanning electron microscope(SEM)showed bimetallic nanoparticles of Cu/Zn-NPs with spherical shape with varying size of 74.33 nm to 59.46 nm.More than 30%mortality of P.solenopsis was observed with Cu/Zn-nanoparticles(100 ppm)at 96 hours after treatment.Negligible mortality of P.solenopsis was recorded with Cu/Zn solution(100 ppm)and aqueous P.juliflora extracts.The results of the viability test for Cu/Zn-nanoparticles of P.juliflora showed a significant reduction of the cell viability by 50%in insect exposed to Cu/Zn-nanoparticles-P.juliflora.Therefore studies about nanotoxicity of Cu/Zn-NPs of P.juliflora are needed to reveal the mechanism of toxicity this phytonanoparticles in P.solenopsis.

Effect of Seasonal Variations and Weather Factors on Population Dynamics of Mango Mealybug (Drosicha mangiferae) in Bangladesh

An experiment was conducted in mango orchard of Sher-E Bangla Agricultural University (SAU) campus, Dhaka to determine the effect of seasonal variation round the year and weather on population dynamics of mango mealybug (Drosicha mangiferae) on mango tree. The mango mealybug was first appeared in early December and disappeared in June in a year. Its population started to increase gradually from December and continued up to February when the ambient average temperature was 20.95°C, relative humidity 63% and rainfall was absent. The highest population of the insect (33.33/30 cm branch) was recorded in February and the lowest (3.75/30cm branch) in May. Adult insects appeared in February on the ground under the selected mango tree showing the population of 6.67 males and 123.33 females per 81 m2. Population of males (32.5/81m2) and that of females (352.75/81m2) reached to the peak when the ambient temperature was 28.19°C, relative humidity 61% and the rainfall was 0.00 mm. When relative humidity was high and rainfall started adult females enter into the soil and disappeared. Correlation between population of mealybug and temperature was positive. Its population was negatively correlated with relative humidity and rainfall.

Parasitic Effects of Solitary Endoparasitoid, Aenasius bambawalei Hayat (Hymenoptera: Encyrtidae) on Cotton Mealybug, Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae)

Parasitization has an enormous impact on host physiology, development and reproduction. The effect of parasitism by endoparasitoid, Aenasius bambawalei Hayat (Hymenoptera: Encyrtidae) on survival and reproduction of mealybug, Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) on different host stages was studied. Our data reveals that host mealybugs parasitized by the wasp at the 2nd instar stage were died during the 3rd instar stage of their life. However, those parasitized at the 3rd instar stage could reach the adult stage and were able to produce their progeny. After 6 days of parasitization, all parasitized hosts of the 2nd, 3rd and adult stages were died except the 1st instar. Results showed that parasitized host mealybugs had significantly lower reproductive potential than the unparasitized ones. Maximum parasitoid emergence was recorded in the 3rd instar host stage. This basic research regarding survival and reproduction of the parasitized host mealybugs would be very helpful in devising sustainable biological control strategies for cotton mealybug.

Inventory and Distribution of Mango Mealybugs Species in Western Burkina Faso: Relative Abundance and Population Fluctuation

Rastrococus invadens was the only reported mealybug species on the mango tree in Western Burkina Faso. This study aimed at carrying out the inventory and showing the importance and distribution of other mealybug species associated with the mango tree. It was also important to determine the periods of abundance of these species vis-a-vis R. invadens. For this purpose, the density of mealybugs was assessed in three study sites (Toussiana, Bérégadougou and Orodara) in Western Burkina Faso. The observations were made from June 2014 to June 2015 at a frequency of 15 ± 1 days. They focused on 20 leaves (5 leaves/cardinal point) levied on each mango tree. The species identified as Ferrisia virgata Cockerell and Icerya aegyptiaca Douglas were collected from mangos infested by R. invadens representing 98% - 99% of the density of the observed mealybug species. The periods of abundance of F. virgata and I. aegyptiaca were respectively the dry season and the rainy season. The effect of temperature, relative humidity and rainfall on the populations of F. virgata and I. aegyptiaca was also discussed. These results highlight the distribution range of F. virgata and I. aegyptiaca worldwide including Burkina Faso. R. invadens was the main mealybug species on mango in Burkina Faso in general and in the Western region of the country in particular.

Inventory and Distribution of Mango Mealybugs Species in Western Burkina Faso: Relative Abundance and Population Fluctuation

Rastrococus invadens was the only reported mealybug species on the mango tree in Western Burkina Faso. This study aimed at carrying out the inventory and showing the importance and distribution of other mealybug species associated with the mango tree. It was also important to determine the periods of abundance of these species vis-a-vis R. invadens. For this purpose, the density of mealybugs was assessed in three study sites (Toussiana, Bérégadougou and Orodara) in Western Burkina Faso. The observations were made from June 2014 to June 2015 at a frequency of 15 ± 1 days. They focused on 20 leaves (5 leaves/cardinal point) levied on each mango tree. The species identified as Ferrisia virgata Cockerell and Icerya aegyptiaca Douglas were collected from mangos infested by R. invadens representing 98% - 99% of the density of the observed mealybug species. The periods of abundance of F. virgata and I. aegyptiaca were respectively the dry season and the rainy season. The effect of temperature, relative humidity and rainfall on the populations of F. virgata and I. aegyptiaca was also discussed. These results highlight the distribution range of F. virgata and I. aegyptiaca worldwide including Burkina Faso. R. invadens was the main mealybug species on mango in Burkina Faso in general and in the Western region of the country in particular.

榕属植物上9种粉蚧雌成虫的显微特征和28S rRNA分子鉴定

为明确榕属植物上粉蚧发生危害的种类,本文应用形态学和分子生物学方法,对榕属植物上调查的粉蚧开展鉴定。通过制作粉蚧雌成虫的玻片标本,从触角、刺孔群、盘孔和管腺等部位详细比较了9种粉蚧的主要显微特征,并制作了检索表。通过28S rRNA基因片段,扩增出38条序列,并与GenBank数据库进行相似性比对,相似度达到99.35%~100%,构建系统进化树,每种粉蚧与GenBank数据库下载的已知序列单独聚在一支,系统进化树结果与形态学鉴定结果一致,结果表明28S rRNA基因片段鉴定粉蚧具有可行性。该方法为农林业监测预警和精准防治粉蚧类害虫提供科学依据。

基于mtDNA COⅠ基因对榕属植物上粉蚧的分子鉴定和系统发育分析

【目的】榕属植物是我国华南地区普遍种植的园林植物,本研究旨在明确榕属植物上发生危害的粉蚧种类。【方法】测定榕属植物上发生为害的9种粉蚧的COⅠ基因序列,利用生物信息学软件分析其序列同源性、遗传结构及系统进化关系。【结果】测出38条粉蚧的COⅠ基因序列相似度达到99.25%~100.00%,9种粉蚧的种间遗传距离为0.070~0.173,其中堆蜡粉蚧与菠萝灰粉蚧遗传距离最大,而康氏粉蚧与橘小粉蚧遗传距离最小,说明康氏粉蚧与橘小粉蚧亲缘关系较近。构建的系统发育树中,每种粉蚧与GenB ank数据库下载的已知序列聚在一支,系统发育树结果与形态学鉴定结果一致。【结论】线粒体COⅠ基因序列能够快速准确鉴定榕属植物上的粉蚧,也揭示了榕属植物上粉蚧的遗传结构和系统进化关系,为农林业监测和精准防治粉蚧类害虫提供科学依据。

暗褐网柄牛肝菌-根粉蚧-植物的营养关系研究进展

暗褐网柄牛肝菌多发生于园艺植物、经济林木或果林等有人类活动的地方,其与宿主不形成菌根结构,非外生菌根菌,具有一定腐生性,但不是典型的腐生食用菌。综述暗褐网柄牛肝菌-根粉蚧-植物形成菌物-动物-植物三界生物协同进化的营养关系:蚧虫寄生于植物根系,汲取寄主植物营养维持自身发育繁殖;暗褐网柄牛肝菌菌丝形成的菌腔为蚧虫提供栖息繁育场所;蚧虫分泌的蜜露对暗褐网柄牛肝菌菌丝生长有促进作用。暗褐网柄牛肝菌产量与菌腔虫瘿数量密切相关,在一定范围内,菌腔虫瘿越多,出菇产量越高。根据这一营养关系提出暗褐网柄牛肝菌人工室内栽培及仿生栽培的适宜方法。

尤溪县柑橘园粉蚧优势种调查及防控药剂筛选

【目的】粉蚧是福建尤溪柑橘园的一种重要害虫,为有效控制其危害,开展该类虫优势种调查及防控药剂筛选。【方法】以尤溪县柑橘主要产区为观测点,调查粉蚧发生种类及相对丰度;测定40%毒死蜱乳油、25%噻嗪酮悬浮剂、5%啶虫胀乳油、22.4%螺虫乙酯悬浮剂和100g/L吡丙醚乳油对粉蚧优势种的室内致死效果,筛选确定理想防控药剂及其适宜的田间使用浓度。【结果】尤溪县柑橘园粉蚧种类有7种,其中橘臀纹粉蚧的相对丰度最高,达59.40%。5种药剂中,22.4%螺虫乙酯悬浮剂和100g/L吡丙醚乳油对橘臀纹粉蚧的室内致死效果最强,药后3d均达100%;22.4%螺虫乙酯悬浮剂3500~4500倍液和100g/L吡丙醚乳油1250~1750倍液的田间防治效果较好,药后15d均达85%以上,性价比较好且无药害产生。【结论】尤溪县柑橘园粉蚧优势种为橘臀纹粉;22.4%螺虫乙酯悬浮剂和100g/L吡丙醚乳油是橘臀纹粉蚧的理想防控药剂,这2种药剂适宜的田间使用浓度分别为3500~4500倍和1250~1750倍。

广东和海南扶桑绵粉蚧的天敌调查

自2009年7月至2010年12月,我们对广东和海南的扶桑绵粉蚧Phenacoccus solenopsis Tinsley的天敌进行调查,共发现8种天敌。其中,捕食性天敌有4种,分别是孟氏隐唇瓢虫Cryptolaemus montrouzieri Mulsant、双带盘瓢虫Lemnia biplagiata(Swartz)、六斑月瓢虫Menochilus sexmaculatus(Fabricius)和圆斑弯叶毛瓢虫Nephus quadrimacu-latus(Kamiya);寄生性天敌有4种,分别是松粉蚧抑虱跳小蜂Acerophagus coccois Smith、班氏跳小蜂Aenasius bam-bawalei Hayat、长崎原长缘跳小蜂Prochiloneurus nagasakiensis(Ishii)和粉蚧广腹细蜂Allotropa sp.。文内简要描述了6种天敌的主要鉴别特征,并提供了一些形态特征图。

警惕检疫性害虫南洋臀纹粉蚧在中国大陆扩散

南洋臀纹粉蚧,又称咖啡粉蚧、可可粉蚧、紫粉蚧,主要危害饮料作物、果树、蔬菜和园林树木,是新近入侵中国大陆的一种危险性检疫性害虫,2012年以来在中国大陆的云南、海南等地陆续被发现。本文介绍了南洋臀纹粉蚧的识别特征、危害特性、寄主植物种类、生物生态学特点、地理分布范围、传播扩散途径和防治措施等,为预防该虫在我国的进一步蔓延提供依据。

利用种特异性COI引物(SS-COI)鉴别扶桑绵粉蚧

扶桑绵粉蚧Phenacoccus solenopsis Tinsley是我国近年新发现的一种严重威胁农林业生产的重要外来入侵害虫。针对扶桑绵粉蚧与其他粉蚧类昆虫难以准确快速识别且适生区广泛的问题,以扶桑绵粉蚧为靶标,以我国常见的其他7种粉蚧为参照,采用基于线粒体DNA细胞色素C氧化酶亚基Ⅰ(mtDNA COI)基因序列的种特异性(species-specific COI,SS-COI)PCR方法,研究其快速分子检测技术。通过已知粉蚧的COI基因序列设计通用型引物1对,获得扶桑绵粉蚧及其他7种粉蚧包括康氏粉蚧Pseudococcus comstocki Kuwana、南洋臀纹粉蚧Planococcus lilacius Cockerell、木槿曼粉蚧Maconellicoccus hirsutus(Green)、甘蔗红粉蚧Saccharicoccus sacchari(Cockerell)、新菠萝灰粉蚧Dysmicoccus neobrevipes Beardsley、番石榴粉蚧Planococcus minor Maskel和石蒜绵粉蚧Phenacoccus solani Ferris的COI基因序列,根据测序结果及数据库中已知粉蚧的COI基因序列设计SS-COI引物1对(PSZTF1/PSZTR1),其扩增片段大小为546bp。种特异性检验结果表明,该引物只对扶桑绵粉蚧的COI基因具有扩增能力,对其他7种粉蚧不具有扩增效果;该引物不仅对成虫具有良好的扩增能力,对不同虫态的扶桑绵粉蚧以及来自我国不同省市的14个地理种群和口岸截获的来自巴基斯坦的扶桑绵粉蚧亦具有同样的扩增效能。这些结果表明,该技术体系完全可用于扶桑绵粉蚧的准确识别及其检测监测,对有效阻截其进一步扩张蔓延意义重大。

我国热区常见粉蚧概述

粉蚧是一类重要的农业害虫,许多种类具有十分相似的外部形态,给日常的鉴定工作增加了难度。在田间调查的基础上结合相关文献对我国热带作物常见粉蚧的分布、寄主及其鉴定特征进行初步总结,并结合外来粉蚧害虫的发生特点提出了防治建议。旨在为我国热区生物多样性的调查及粉蚧的有效防治提供指导。